In many cases, aneurysms form in the vessel walls of an organism. If such an aneurysm were to rupture, the organism would be in danger of severely bleeding from the rupture site. Depending on the location of the aneurysm, its rupture could lead to stroke. And if large enough, the aneurysm's rupture could even lead to exsanguination.
The extreme risks associated with aneurysms call for their treatment. Typical treatments of un-ruptured aneurysms include surgically removing them in situations where such removal is possible. Another treatment centers on filling an aneurysm sack with coils of various materials, which may decrease the pressure in the sack. In some cases, the danger from the aneurysm decreases when the pressure in the sack falls. To reduce the pressure in the sack, it is important to fill the sack well, and then slowly allow the sack to fill up with scarring or other extracellular matrix material. A practitioner could orchestrate slow filling followed by scarring or the migration of other matrix material using coils with bioabsorbable, pro-inflammatory coatings. Alternatively, changes in the hemodynamics cause by filling the aneurysm promote the formation of thrombus inside the aneurysm sack, which also lowers aneurysm pressure.
In many cases, filling treatment results in an aneurysm permanently filled with foreign material. This treatment may lower the pressure and restore normal hemodynamics near the aneurysm. But it also interferes with the aneurysm's complete healing.
What is needed is a way to temporarily fill the aneurysm in a controllable manner such that endogenous compounds could later gradually replace the filling material.